In-paddock cattle weighing – Optiweigh

Tom Gooden from Growth Farms Australia is based at Camperdown in Victoria and is using Optiweigh to monitor steer and heifer weights. It has allowed them to track steer liveweight gain to ensure they will meet forward contracts on time.

Their 40 heifers had an average weaning weight of 230kg in October and were expected to reach an average pre-mating weight of 330kg in June. The heifers' feed budget ensured they gained a minimum of 300g per day prior to joining. However, the grain utilisation was poor and Optiweigh indicated the heifers were maintaining condition, not gaining weight.

Tom was skeptical of the Optiweigh data and brought the heifers in to be yard weighed. The average weight displayed by Optiweigh was accurate and Tom altered the ration, moving the heifers onto a paddock with more pasture availability.

Throughout 240 days on feed, the farm staff would usually yard weigh the heifers 5 times. By using Optiweigh, yard weighing was reduced to 2 times.

Not all the heifers visited the Optiweigh while it was in the paddock. On average, 50% of the mob were weighed between 6 to 22 times during a 3-month period. This provides sufficient information on average mob performance to inform feeding and management decisions.

^{Proportion of the mob that visited the Optiweigh between March and July}

The farm has low 3G connectivity, but it is adequate to transmit data on a daily basis.

Tom is saving on labour to weigh stock monthly and can objectively measure performance at any time. He believes the Optiweigh will pay for itself within a few years.

Tom advised Optiweigh users to monitor the attractant used. From his experience, molasses was the best to attract the cattle rather than salt, but experiences could differ.

Weights taken with Optiweigh compared with weights measured in the yards:

The below table demonstrates 3 scenarios to compare the costs of:

• monitoring heifer weight by regular yard weighing only
• an undetected decrease in heifer weight with less frequent yard weighing
• monitoring heifer weight using Optiweigh and minimal yard weighing.

Estimated ROI is based on using Optiweigh to monitor a mob of 40 heifers over 8 months. If the average liveweight loss is detected early, the return on investment of using the Optiweigh is realised in the first year. If an issue is detected with Optiweigh, there will be a 136% return.

1. Induction weight was 230kg with a target weight of 330kg over an 8-month period. Estimated liveweight loss of 1.5% of average body weight from yard weighing.
2. Labour estimated based on $50 per hour for 2 people, at 2.5 hours each weighing event.
3. Motor vehicle costs estimated at $0.72 per km for an average of 10km return trip.
4. Costs based on $5 per kg.
5. Estimated conception loss of 10%, from an expected 95% conception rate, caused by undetected liveweight loss.
6. Estimated production based on loss of a steer sold at 450kg at $5 per kg.

The ROI is realised when weight loss is detected and can be immediately rectified. Utilising the Optiweigh over a larger number of cattle improves the ROI from what is described.

The Optiweigh can also track average daily gain to ensure cattle reach a target weight at the right time, further adding to the ROI.

The ROI excludes the Optiweigh costs (current as of February 2022):

• purchase price: $17,000 excluding GST
• ongoing data subscription costs: $240 per year.